diff --git a/src/DotSwashbuckle.AspNetCore.Newtonsoft/SchemaGenerator/NewtonsoftDataContractResolver.cs b/src/DotSwashbuckle.AspNetCore.Newtonsoft/SchemaGenerator/NewtonsoftDataContractResolver.cs
index 1b4ac8693b..3c2830de09 100644
--- a/src/DotSwashbuckle.AspNetCore.Newtonsoft/SchemaGenerator/NewtonsoftDataContractResolver.cs
+++ b/src/DotSwashbuckle.AspNetCore.Newtonsoft/SchemaGenerator/NewtonsoftDataContractResolver.cs
@@ -33,7 +33,7 @@ public DataContract GetDataContractForType(Type type)
 
             if (jsonContract is JsonPrimitiveContract && !jsonContract.UnderlyingType.IsEnum)
             {
-                var primitiveTypeAndFormat = PrimitiveTypesAndFormats.TryGetValue(jsonContract.UnderlyingType, out var format)
+                var primitiveTypeAndFormat = CommonFormats.PrimitiveTypesAndFormats.TryGetValue(jsonContract.UnderlyingType, out var format)
                     ? format
                     : Tuple.Create(DataType.String, (string)null);
 
@@ -53,8 +53,8 @@ public DataContract GetDataContractForType(Type type)
                     && JsonConverterFunc(enumValues.GetValue(0)).StartsWith("\"");
 
                 var primitiveTypeAndFormat = serializeAsString
-                    ? PrimitiveTypesAndFormats[typeof(string)]
-                    : PrimitiveTypesAndFormats[jsonContract.UnderlyingType.GetEnumUnderlyingType()];
+                    ? CommonFormats.PrimitiveTypesAndFormats[typeof(string)]
+                    : CommonFormats.PrimitiveTypesAndFormats[jsonContract.UnderlyingType.GetEnumUnderlyingType()];
 
                 return DataContract.ForPrimitive(
                     underlyingType: jsonContract.UnderlyingType,
@@ -183,50 +183,5 @@ private IEnumerable<DataProperty> GetDataPropertiesFor(JsonObjectContract jsonOb
 
             return dataProperties;
         }
-
-        private static readonly Dictionary<Type, Tuple<DataType, string>> PrimitiveTypesAndFormats = new Dictionary<Type, Tuple<DataType, string>>
-        {
-            [typeof(bool)] = Tuple.Create(DataType.Boolean, (string)null),
-            [typeof(bool?)] = Tuple.Create(DataType.Boolean, (string)null),
-            [typeof(byte)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(byte?)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(sbyte)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(sbyte?)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(short)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(short?)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(ushort)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(ushort?)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(int)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(int?)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(uint)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(uint?)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(long)] = Tuple.Create(DataType.Integer, "int64"),
-            [typeof(long?)] = Tuple.Create(DataType.Integer, "int64"),
-            [typeof(ulong)] = Tuple.Create(DataType.Integer, "int64"),
-            [typeof(ulong?)] = Tuple.Create(DataType.Integer, "int64"),
-            [typeof(float)] = Tuple.Create(DataType.Number, "float"),
-            [typeof(float?)] = Tuple.Create(DataType.Number, "float"),
-            [typeof(double)] = Tuple.Create(DataType.Number, "double"),
-            [typeof(double?)] = Tuple.Create(DataType.Number, "double"),
-            [typeof(decimal)] = Tuple.Create(DataType.Number, "double"),
-            [typeof(decimal?)] = Tuple.Create(DataType.Number, "double"),
-            [typeof(byte[])] = Tuple.Create(DataType.String, "byte"),
-            [typeof(string)] = Tuple.Create(DataType.String, (string)null),
-            [typeof(char)] = Tuple.Create(DataType.String, (string)null),
-            [typeof(char?)] = Tuple.Create(DataType.String, (string)null),
-            [typeof(DateTime)] = Tuple.Create(DataType.String, "date-time"),
-            [typeof(DateTime?)] = Tuple.Create(DataType.String, "date-time"),
-            [typeof(DateTimeOffset)] = Tuple.Create(DataType.String, "date-time"),
-            [typeof(DateTimeOffset?)] = Tuple.Create(DataType.String, "date-time"),
-            [typeof(Guid)] = Tuple.Create(DataType.String, "uuid"),
-            [typeof(Guid?)] = Tuple.Create(DataType.String, "uuid"),
-            [typeof(Uri)] = Tuple.Create(DataType.String, "uri"),
-            [typeof(TimeSpan)] = Tuple.Create(DataType.String, "date-span"),
-            [typeof(TimeSpan?)] = Tuple.Create(DataType.String, "date-span"),
-            [typeof(DateOnly)] = Tuple.Create(DataType.String, "date"),
-            [typeof(DateOnly?)] = Tuple.Create(DataType.String, "date"),
-            [typeof(TimeOnly)] = Tuple.Create(DataType.String, "time"),
-            [typeof(TimeOnly?)] = Tuple.Create(DataType.String, "time")
-        };
     }
 }
diff --git a/src/DotSwashbuckle.AspNetCore.SwaggerGen/SchemaGenerator/JsonSerializerDataContractResolver.cs b/src/DotSwashbuckle.AspNetCore.SwaggerGen/SchemaGenerator/JsonSerializerDataContractResolver.cs
index b7080cd3a3..941193c0fa 100644
--- a/src/DotSwashbuckle.AspNetCore.SwaggerGen/SchemaGenerator/JsonSerializerDataContractResolver.cs
+++ b/src/DotSwashbuckle.AspNetCore.SwaggerGen/SchemaGenerator/JsonSerializerDataContractResolver.cs
@@ -26,7 +26,7 @@ public DataContract GetDataContractForType(Type type)
                     jsonConverter: JsonConverterFunc);
             }
 
-            if (PrimitiveTypesAndFormats.TryGetValue(type, out var primitiveTypeAndFormat1))
+            if (CommonFormats.PrimitiveTypesAndFormats.TryGetValue(type, out var primitiveTypeAndFormat1))
             {
                 return DataContract.ForPrimitive(
                     underlyingType: type,
@@ -44,8 +44,8 @@ public DataContract GetDataContractForType(Type type)
                     && JsonConverterFunc(enumValues.GetValue(0)).StartsWith("\"");
 
                 var primitiveTypeAndFormat = serializeAsString
-                    ? PrimitiveTypesAndFormats[typeof(string)]
-                    : PrimitiveTypesAndFormats[type.GetEnumUnderlyingType()];
+                    ? CommonFormats.PrimitiveTypesAndFormats[typeof(string)]
+                    : CommonFormats.PrimitiveTypesAndFormats[type.GetEnumUnderlyingType()];
 
                 return DataContract.ForPrimitive(
                     underlyingType: type,
@@ -211,48 +211,5 @@ private IEnumerable<DataProperty> GetDataPropertiesFor(Type objectType, out Type
 
             return dataProperties;
         }
-
-        private static readonly Dictionary<Type, Tuple<DataType, string>> PrimitiveTypesAndFormats = new Dictionary<Type, Tuple<DataType, string>>
-        {
-            [typeof(bool)] = Tuple.Create(DataType.Boolean, (string)null),
-            [typeof(bool?)] = Tuple.Create(DataType.Boolean, (string)null),
-            [typeof(byte)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(byte?)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(sbyte)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(sbyte?)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(short)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(short?)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(ushort)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(ushort?)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(int)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(int?)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(uint)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(uint?)] = Tuple.Create(DataType.Integer, "int32"),
-            [typeof(long)] = Tuple.Create(DataType.Integer, "int64"),
-            [typeof(long?)] = Tuple.Create(DataType.Integer, "int64"),
-            [typeof(ulong)] = Tuple.Create(DataType.Integer, "int64"),
-            [typeof(ulong?)] = Tuple.Create(DataType.Integer, "int64"),
-            [typeof(float)] = Tuple.Create(DataType.Number, "float"),
-            [typeof(float?)] = Tuple.Create(DataType.Number, "float"),
-            [typeof(double)] = Tuple.Create(DataType.Number, "double"),
-            [typeof(double?)] = Tuple.Create(DataType.Number, "double"),
-            [typeof(decimal)] = Tuple.Create(DataType.Number, "double"),
-            [typeof(decimal?)] = Tuple.Create(DataType.Number, "double"),
-            [typeof(byte[])] = Tuple.Create(DataType.String, "byte"),
-            [typeof(string)] = Tuple.Create(DataType.String, (string)null),
-            [typeof(char)] = Tuple.Create(DataType.String, (string)null),
-            [typeof(char?)] = Tuple.Create(DataType.String, (string)null),
-            [typeof(DateTime)] = Tuple.Create(DataType.String, "date-time"),
-            [typeof(DateTime?)] = Tuple.Create(DataType.String, "date-time"),
-            [typeof(DateTimeOffset)] = Tuple.Create(DataType.String, "date-time"),
-            [typeof(DateTimeOffset?)] = Tuple.Create(DataType.String, "date-time"),
-            [typeof(Guid)] = Tuple.Create(DataType.String, "uuid"),
-            [typeof(Guid?)] = Tuple.Create(DataType.String, "uuid"),
-            [typeof(Uri)] = Tuple.Create(DataType.String, "uri"),
-            [typeof(DateOnly)] = Tuple.Create(DataType.String, "date"),
-            [typeof(DateOnly?)] = Tuple.Create(DataType.String, "date"),
-            [typeof(TimeOnly)] = Tuple.Create(DataType.String, "time"),
-            [typeof(TimeOnly?)] = Tuple.Create(DataType.String, "time")
-        };
     }
 }
diff --git a/src/DotSwashbuckle.AspNetCore.SwaggerGen/SchemaGenerator/PrimitiveTypesAndFormats.cs b/src/DotSwashbuckle.AspNetCore.SwaggerGen/SchemaGenerator/PrimitiveTypesAndFormats.cs
new file mode 100644
index 0000000000..7611f8d41f
--- /dev/null
+++ b/src/DotSwashbuckle.AspNetCore.SwaggerGen/SchemaGenerator/PrimitiveTypesAndFormats.cs
@@ -0,0 +1,58 @@
+using System;
+using System.Collections.Generic;
+
+namespace DotSwashbuckle.AspNetCore.SwaggerGen
+{
+    public static class CommonFormats
+    {
+        public static readonly IReadOnlyDictionary<Type, Tuple<DataType, string>> PrimitiveTypesAndFormats = new Dictionary<Type, Tuple<DataType, string>>
+        {
+            [typeof(bool)] = Tuple.Create(DataType.Boolean, (string)null),
+            [typeof(bool?)] = Tuple.Create(DataType.Boolean, (string)null),
+            [typeof(byte)] = Tuple.Create(DataType.Integer, "int32"),
+            [typeof(byte?)] = Tuple.Create(DataType.Integer, "int32"),
+            [typeof(sbyte)] = Tuple.Create(DataType.Integer, "int32"),
+            [typeof(sbyte?)] = Tuple.Create(DataType.Integer, "int32"),
+            [typeof(short)] = Tuple.Create(DataType.Integer, "int32"),
+            [typeof(short?)] = Tuple.Create(DataType.Integer, "int32"),
+            [typeof(ushort)] = Tuple.Create(DataType.Integer, "int32"),
+            [typeof(ushort?)] = Tuple.Create(DataType.Integer, "int32"),
+            [typeof(int)] = Tuple.Create(DataType.Integer, "int32"),
+            [typeof(int?)] = Tuple.Create(DataType.Integer, "int32"),
+            [typeof(uint)] = Tuple.Create(DataType.Integer, "int32"),
+            [typeof(uint?)] = Tuple.Create(DataType.Integer, "int32"),
+            [typeof(long)] = Tuple.Create(DataType.Integer, "int64"),
+            [typeof(long?)] = Tuple.Create(DataType.Integer, "int64"),
+            [typeof(ulong)] = Tuple.Create(DataType.Integer, "int64"),
+            [typeof(ulong?)] = Tuple.Create(DataType.Integer, "int64"),
+            [typeof(Int128)] = Tuple.Create(DataType.Integer, "int128"),
+            [typeof(Int128?)] = Tuple.Create(DataType.Integer, "int128"),
+            [typeof(UInt128)] = Tuple.Create(DataType.Integer, "int128"),
+            [typeof(UInt128?)] = Tuple.Create(DataType.Integer, "int128"),
+            [typeof(Version)] = Tuple.Create(DataType.String, (string)null),
+            [typeof(float)] = Tuple.Create(DataType.Number, "float"),
+            [typeof(float?)] = Tuple.Create(DataType.Number, "float"),
+            [typeof(double)] = Tuple.Create(DataType.Number, "double"),
+            [typeof(double?)] = Tuple.Create(DataType.Number, "double"),
+            [typeof(decimal)] = Tuple.Create(DataType.Number, "double"),
+            [typeof(decimal?)] = Tuple.Create(DataType.Number, "double"),
+            [typeof(byte[])] = Tuple.Create(DataType.String, "byte"),
+            [typeof(string)] = Tuple.Create(DataType.String, (string)null),
+            [typeof(char)] = Tuple.Create(DataType.String, (string)null),
+            [typeof(char?)] = Tuple.Create(DataType.String, (string)null),
+            [typeof(DateTime)] = Tuple.Create(DataType.String, "date-time"),
+            [typeof(DateTime?)] = Tuple.Create(DataType.String, "date-time"),
+            [typeof(DateTimeOffset)] = Tuple.Create(DataType.String, "date-time"),
+            [typeof(DateTimeOffset?)] = Tuple.Create(DataType.String, "date-time"),
+            [typeof(Guid)] = Tuple.Create(DataType.String, "uuid"),
+            [typeof(Guid?)] = Tuple.Create(DataType.String, "uuid"),
+            [typeof(Uri)] = Tuple.Create(DataType.String, "uri"),
+            [typeof(TimeSpan)] = Tuple.Create(DataType.String, "date-span"),
+            [typeof(TimeSpan?)] = Tuple.Create(DataType.String, "date-span"),
+            [typeof(DateOnly)] = Tuple.Create(DataType.String, "date"),
+            [typeof(DateOnly?)] = Tuple.Create(DataType.String, "date"),
+            [typeof(TimeOnly)] = Tuple.Create(DataType.String, "time"),
+            [typeof(TimeOnly?)] = Tuple.Create(DataType.String, "time")
+        };
+    }
+}
diff --git a/test/DotSwashbuckle.AspNetCore.Newtonsoft.Test/SchemaGenerator/NewtonsoftSchemaGeneratorTests.cs b/test/DotSwashbuckle.AspNetCore.Newtonsoft.Test/SchemaGenerator/NewtonsoftSchemaGeneratorTests.cs
index 64d3da6a76..8259a0165e 100644
--- a/test/DotSwashbuckle.AspNetCore.Newtonsoft.Test/SchemaGenerator/NewtonsoftSchemaGeneratorTests.cs
+++ b/test/DotSwashbuckle.AspNetCore.Newtonsoft.Test/SchemaGenerator/NewtonsoftSchemaGeneratorTests.cs
@@ -53,6 +53,8 @@ public void GenerateSchema_GeneratesFileSchema_IfFormFileOrFileResultType(Type t
         [InlineData(typeof(float), "number", "float", false)]
         [InlineData(typeof(double), "number", "double", false)]
         [InlineData(typeof(decimal), "number", "double", false)]
+        [InlineData(typeof(Int128), "integer", "int128", false)]
+        [InlineData(typeof(UInt128), "integer", "int128", false)]
         [InlineData(typeof(string), "string", null, false)]
         [InlineData(typeof(char), "string", null, false)]
         [InlineData(typeof(byte[]), "string", "byte", false)]
@@ -63,6 +65,8 @@ public void GenerateSchema_GeneratesFileSchema_IfFormFileOrFileResultType(Type t
         [InlineData(typeof(Version), "string", null, false)]
         [InlineData(typeof(bool?), "boolean", null, true)]
         [InlineData(typeof(int?), "integer", "int32", true)]
+        [InlineData(typeof(Int128?), "integer", "int128", true)]
+        [InlineData(typeof(UInt128?), "integer", "int128", true)]
         [InlineData(typeof(DateTime?), "string", "date-time", true)]
         public void GenerateSchema_GeneratesPrimitiveSchema_IfPrimitiveOrNullablePrimitiveType(
             Type type,
diff --git a/test/DotSwashbuckle.AspNetCore.SwaggerGen.Test/SchemaGenerator/JsonSerializerSchemaGeneratorTests.cs b/test/DotSwashbuckle.AspNetCore.SwaggerGen.Test/SchemaGenerator/JsonSerializerSchemaGeneratorTests.cs
index c622453717..654af0fb8a 100644
--- a/test/DotSwashbuckle.AspNetCore.SwaggerGen.Test/SchemaGenerator/JsonSerializerSchemaGeneratorTests.cs
+++ b/test/DotSwashbuckle.AspNetCore.SwaggerGen.Test/SchemaGenerator/JsonSerializerSchemaGeneratorTests.cs
@@ -44,42 +44,44 @@ public void GenerateSchema_GeneratesFileSchema_IfFormFileOrFileResultType(Type t
         }
 
         [Theory]
-        [InlineData(typeof(bool), "boolean", null)]
-        [InlineData(typeof(byte), "integer", "int32")]
-        [InlineData(typeof(sbyte), "integer", "int32")]
-        [InlineData(typeof(short), "integer", "int32")]
-        [InlineData(typeof(ushort), "integer", "int32")]
-        [InlineData(typeof(int), "integer", "int32")]
-        [InlineData(typeof(uint), "integer", "int32")]
-        [InlineData(typeof(long), "integer", "int64")]
-        [InlineData(typeof(ulong), "integer", "int64")]
-        [InlineData(typeof(float), "number", "float")]
-        [InlineData(typeof(double), "number", "double")]
-        [InlineData(typeof(decimal), "number", "double")]
-        [InlineData(typeof(string), "string", null)]
-        [InlineData(typeof(char), "string", null)]
-        [InlineData(typeof(byte[]), "string", "byte")]
-        [InlineData(typeof(DateTime), "string", "date-time")]
-        [InlineData(typeof(DateTimeOffset), "string", "date-time")]
-        [InlineData(typeof(Guid), "string", "uuid")]
-        [InlineData(typeof(Uri), "string", "uri")]
-        [InlineData(typeof(DateOnly), "string", "date")]
-        [InlineData(typeof(TimeOnly), "string", "time")]
-        [InlineData(typeof(bool?), "boolean", null)]
-        [InlineData(typeof(int?), "integer", "int32")]
-        [InlineData(typeof(DateTime?), "string", "date-time")]
-        [InlineData(typeof(Guid?), "string", "uuid")]
-        [InlineData(typeof(DateOnly?), "string", "date")]
-        [InlineData(typeof(TimeOnly?), "string", "time")]
+        [InlineData(typeof(byte), "integer", "int32", false)]
+        [InlineData(typeof(sbyte), "integer", "int32", false)]
+        [InlineData(typeof(short), "integer", "int32", false)]
+        [InlineData(typeof(ushort), "integer", "int32", false)]
+        [InlineData(typeof(int), "integer", "int32", false)]
+        [InlineData(typeof(uint), "integer", "int32", false)]
+        [InlineData(typeof(long), "integer", "int64", false)]
+        [InlineData(typeof(ulong), "integer", "int64", false)]
+        [InlineData(typeof(float), "number", "float", false)]
+        [InlineData(typeof(double), "number", "double", false)]
+        [InlineData(typeof(decimal), "number", "double", false)]
+        [InlineData(typeof(Int128), "integer", "int128", false)]
+        [InlineData(typeof(UInt128), "integer", "int128", false)]
+        [InlineData(typeof(string), "string", null, false)]
+        [InlineData(typeof(char), "string", null, false)]
+        [InlineData(typeof(byte[]), "string", "byte", false)]
+        [InlineData(typeof(DateTime), "string", "date-time", false)]
+        [InlineData(typeof(DateTimeOffset), "string", "date-time", false)]
+        [InlineData(typeof(Guid), "string", "uuid", false)]
+        [InlineData(typeof(TimeSpan), "string", "date-span", false)]
+        [InlineData(typeof(Version), "string", null, false)]
+        [InlineData(typeof(bool?), "boolean", null, true)]
+        [InlineData(typeof(int?), "integer", "int32", true)]
+        [InlineData(typeof(Int128?), "integer", "int128", true)]
+        [InlineData(typeof(UInt128?), "integer", "int128", true)]
+        [InlineData(typeof(DateTime?), "string", "date-time", true)]
         public void GenerateSchema_GeneratesPrimitiveSchema_IfPrimitiveOrNullablePrimitiveType(
             Type type,
             string expectedSchemaType,
-            string expectedFormat)
+            string expectedFormat,
+            bool expectedNullable
+        )
         {
             var schema = Subject().GenerateSchema(type, new SchemaRepository());
 
             Assert.Equal(expectedSchemaType, schema.Type);
             Assert.Equal(expectedFormat, schema.Format);
+            Assert.Equal(expectedNullable, schema.Nullable);
         }
 
         [Theory]